Inhaler

ABSTRACT

Device for use with an inhaler, the inhaler having a body, an aerosol canister arranged in the body containing medicament, including a metered dose chamber and able to dispense a metered dose of the medicament, a nozzle in fluid communication with the canister, an opening for dispensing of the medicament in fluid communication with the nozzle. The device includes elements for activating the canister to open and dispense the medicament in response to an airflow in the inhaler caused by inhalation of a user through the opening, return elements for deactivating the canister to close it, characterized in that the return elements deactivate the canister when the airflow drops below a certain threshold value.

This application is a division of Application Ser. No. 10/018,242, filedon Oct. 1, 2002 now U.S. Pat. No. 6,866,037, Application Ser. No.10/018,242 is the national phase of PCT International Application No.PCT/SE/01278 filed on Jun. 16, 2000 under 35 U.S.C. § 371. The entirecontents of each of the above-identified applications are herebyincorporated by reference.

TECHNICAL FIELD

The present invention relates to an inhaler, the inhaler comprising abody, a compartment arranged in said body containing medicament,comprising a number of doses, which inhaler is able to dispense ametered dose of said medicament, and an opening for dispensing of saidmedicament.

BACKGROUND OF THE INVENTION

For a number of years inhalers have been used to deliver a metered doseof medicament to the respiratory tract of a patient. Basically there arethree types of inhalers, adapted for powder medicament, aerosol drivenfluid medicament and nebulisers.

The primary design of most of the inhalers are basically the same forthe different forms of medicament; a housing containing a supply of themedicament, a mouthpiece, air flow conduits in connection with thesupply of medicament and activating means for generating delivery of ametered dose of medicament. The activating means have a wide variety ofconstructions and functions. These include activation by the patient'shand, such as squeezing the inhaler or manoeuvring a button, duringinhalation, electrically activated dose delivery, and inhalationactivated dose delivery, for example.

Apart from delivery of a metered dose, most inhalers are also arrangedwith refilling/recharging means, that is, the chamber or compartmentcontaining the metered dose has to be refilled/recharged after delivery,or before the next dose is to be delivered.

The drawback of the patient activated inhalers is that it may bedifficult for some persons to activate the inhaler and inhale at thesame instant. If these actions are not quite synchronised, the patientreceives an inadequate amount of medicament into the respiratory tract.Many of the recent designs of inhalers are therefore breath activatedwherein the device is activated by inhalation. This causes the canisterto be depressed and deliver its metered dose.

One problem with these inhalers is that the canister remains depresseduntil the patient physically intervenes and removes the pressure on thecanister. The chamber may not be refilled completely with these types ofinhalers, especially when the amount remaining in the canister is low,because the user may hold the canister of the inhaler in a non-verticalposition during the action activating/refilling of the inhalers metereddose chamber. If the level of medicament is low, it cannot then flowinto the metered dose chamber in this position. Instead the chamber isfilled with the propellant gas. During the subsequent dose, the patientwill receive a reduced dose of medicament, perhaps only propellant gas.

Another problem with some breath-activated inhalers is that the inhalerallows for the canister to be compressed for substantial periods oftime, resulting in reduced functionality of the valve mechanism.

Document U.S. Pat. No. 5,826,571 discloses a breath-activated inhalercomprising an activating means which depresses the canister in responseto inhalation and return means for automatically deactivating ornon-depressing the canister in response to the activating means. Theinhaler further comprises control means for controlling the time thecanister is open, i e the time between activation and deactivation. Thereturn means also provides a refill of the metered dose chamber of thecanister during deactivation.

One problem associated with the above inhaler is that the devicecontrols the opening time of the canister, i e the time the canister isdepressed, in order to insure that the whole dose is delivered. With thecanisters presently on the market, the pressure is such that the majorpart of the metered dose is delivered during the first 200-300 ms afterthe canister opens. A remaining part is delivered during the subsequentperiod of time. For the previous breath-activated inhalers, the openingtime posed no problem, since the canister remained open after activationuntil it was physically recharged. With the inhaler according to U.S.Pat. No. 5,826,571 the opening time controls the return means todeactivate the canister. A further aspect in this respect is therepeatability of the inhaler, which is one of the requirements of such aproduct from national authorities approving medicaments and productsassociated with these.

The opening time of U.S. Pat. No. 5,826,571 is controlled by aviscoelastic element. This element may be adjusted so that the requiredopening time is obtained when the inhaler is assembled at the factory,and even during some period of use. But repeated use, and time itself,will likely change the properties of the viscoelastic element so thatthe opening time varies. If shorter, the whole metered dose will not bedelivered to the patient, with a deteriorated inhalation quality as aconsequence due to doses delivered that are inadequate to the patient.

On the other hand, if the opening time is too long, the patient mayremove the inhaler from the mouth and position it in a non-verticalposition before the canister is closed and the metered dose chamber isclosed. If the level of medicament then is low an inadequate refill ofthe chamber is obtained, as described above, and the patient does notreceive its correct medicament during the subsequent inhalation.

A general problem with the known inhalers is that there is nopossibility of monitoring or controlling the inhalation quality of thepatient, and from that obtain an indication on the medication, sinceonly the start of the inhalation activates the device.

Another aspect in this technical field is that many medical distributionproducts today have some sort of drug container comprising a number ofdoses of medicament and a drug delivery opening through which themedicament is delivered. For example these comprise inhalers such asaerosol inhalers where the medicament and propellant is contained in acanister or the like. The canister comprises a hollow stem through whichthe medicament is delivered when the stem is pressed into the canister.Other inhalers have the medicament in powder form, where the powder iscontained in blisters or the like. When the medicament is to bedelivered, the blister is opened, either by tearing the blister open orby piercing it so that an opening is created. With nebulisers, anampoule or blister or other container holding the medicament is piercedor slit open.

Other medical distribution products are injectors where the medicamentis contained in a syringe, which in turn is placed in a casing, whichinjectors automatically or semi-automatically perform differentfunctions such as injecting the needle into the patient, delivering themedicament from the syringe and retracting the needle or ejecting aneedle protector.

For the drug to be delivered from these devices, they are provided withsome kind of actuating means. These often comprise springs or the likewhich could be “energised” i e tensioned and held in that state untilthey are released. The actuating means could be energised eithermanually by a lever, sliding button or the like tensioning the actuatingmeans or automatically whereby they are tensioned by moving componentsof the device. In order to be held in an energised state, the devicescomprise a locking means capable of holding the actuating means in anenergised state. Depending on device, the actuating means, when releasedby the locking means, depress a canister, puncture a blister or ampouleor push the plunger of a syringe, etc.

The devices further comprise some sort of activating means operationallyattached to the actuating means and capable of releasing the lockingmeans when the patient is to receive a dose of medicament. Theseactuating means could be purely manually operated, such as a button, alever or a handle arranged on the outer surface of the device. Thepatient then presses or moves the activating means in order to releasethe locking means.

For many inhalers, the activating means is a flap or a vane that isarranged adjacent an air intake on the inhaler and substantiallyblocking the air intake when not activated. When a patient inhalesthrough an inhalation opening, a pressure difference occurs over thevane or flap. This pressure difference causes the flap or vane to moveand thereby open the air intake so that an inhalation air flow iscreated. This movement of the flap or vane releases the locking means sothat the actuating means is activated and a dose is delivered.

The spring means of the actuating means are often rather powerful. Forinstance with aerosol driven inhalers the spring means have to be ableto depress the canister so that a dose is delivered. This means that astem of the canister has to be pushed into the canister against thespring force of the stem and against the friction caused by the sealsaround the stem.

For auto-injectors there could be several actuating means. Firstly theneedle has to be pushed into the patient. Then the plunger is pressedinto the syringe in order to deliver the medicament. After the drug isdelivered, the needle is withdrawn either by retracting it into theauto-injector housing or by pushing forward a needle protection means.

The fact that the force of the actuating means is relatively high andthat it thus requires relatively high forces in order to hold or lock itin an energised state, at the same time as the forces for activating theactuating means need to be low, requires some form of transmission inorder for the low activating force to be able to release the actuatingforce. It may be seen as one single energy system where a small inputforce provides a large output force.

Because of this relation, quite a number of components are required,which components will affect the energy system due to for examplefriction of components, tolerances and spring characteristics, givingrise to variations in force required for releasing the actuating means.Because it is one single interconnected system, the force for activatingthe activating means will thus also vary.

For most medical devices this is not acceptable because the activationshould occur within a relatively narrow, well-defined force range. Inorder to cope with this, conventional techniques for these devices tryto keep the number of components to a minimum and with high demands ontolerances in order to minimise the variations, in order to try toobtain predictable and repetitive conditions.

The strive to keep the number of component down and working with hightolerance requirements gives a rather costly device, by which it even sois difficult to manage all conditions.

One example is aerosol inhalers, where one, due to environmentalconsiderations, is switching from canisters with CFC as propellant toHFA. HFA however requires much stronger seals whereby the force requiredto depress the canister may be substantially higher than for theCFC-canisters. With the same activating means, the variations willincrease in the same degree. In order to cope with this, even higherdemands on tolerances are required.

The above mentioned problems are also very much pronounced with somedevices, such as multiple automatic functions acting in sequence of eachother, with long and/or multiple energy systems where it is importantthat the forces required for triggering the different actuating meansare certain to be provided without over dimensioning the activatingmeans. Otherwise, either it is not certain that the different functionsare able to sequentially trigger each other or the device will beunnecessarily bulky and difficult to use.

According to a further aspect on inhalers, the main object with thebreath activation is to facilitate for the patient to obtain a dose ofmedicament, in comparison to the manually operated inhalers where thepatient needs to activate the delivery by hand and inhale at the sametime. This co-ordination of actions from the patient often causesproblems so that, if the patient do not co-ordinate properly, thepatient may not receive an adequate dose of medicament.

In the case of aerosol driven inhalers the breath-activation causes aspring to compress a canister containing the medicament and propellantso that the medicament is delivered. Either a metered dose is deliveredor the canister is open a predetermined time under which time medicamentis delivered continuously. In the case of powder inhalers, the breathactivation causes access to an amount of powder to be inhaled or a doseto be delivered. Other types of inhalers, such as nebulizers, may alsohave breath-activated devices for activating the delivery of a dose, orquantity, of medicament.

Some of the breath-activated devices comprise some form of plate-shapedlid, flap or vane movably arranged in an air flow path in the inhaler oradjacent an air intake. Upon inhalation the pressure drop and/or airflow causes the plate to move and thereby activate the actuating meansso that a dose is delivered.

Some of the breath-activated inhalers are also arranged with returnmeans. These return means “reset” the actuating means to a ready stateso that the inhaler is ready for use for the subsequent inhalation. Thereturn means also recharge the inhaler, e g refills a metered dosechamber with medicament for subsequent use. The return means are eitheroperated manually, e g when a protective cover is closed or opened, orautomatically, either at a specific time after inhalation or when theinhalation is terminated.

A drawback with the above described devices is that the breath-activateddevices may unintentionally be triggered when the inhaler is ready forinhalation if the inhaler is dropped or otherwise exposed to suddenforces. Since the plates, vanes or flaps should be able to move byrather small forces exerted by the pressure drop/air flow duringinhalation, they might also rather easily be moved by a sudden movementor sudden change of movement of the inhaler, such as if the inhaler isshaken or hits an object when it is ready for inhalation.

A number of doses important to the patient could be lost in this way.Further, the doses will, for many types of inhalers, be delivered insidethe inhaler if triggered unintentionally. The medicament deliveredinside the inhaler may deposition passage ways or mechanisms of theinhaler and possibly obstruct the function or rendering the inhalerunclean. The deposition may also affect the dose-to-dose equivalence inthat a lesser amount of medicament is inhaled than intended, and in thatthe deposited medicament may break loose during inhalation, whereby theamount is larger than intended.

In context with inhalers with automatic recharging means, an unintendedtriggering of the inhaler may also lead to an improper filling of themetered dose chamber if for example the inhaler is held in such aposition during recharging that the medicament cannot properly fill thechamber. This could for example be the case with aerosol drivencanisters that have to be held in a substantially vertical position whenrefilling the metered dose chamber, in particular when the canister isnot full. The improper filling of the metered dose chamber leads to animproper dose delivered to the patient at the subsequent inhalation.

At the present, there is a wide variety of inhalers on the market, wherea large quantity of these are so called aerosol-driven inhalers. Thesecomprise a canister comprising the medicament and a gas as propellant.The canister comprises a dispensing device with a spring-loaded stem.When the stem is pressed into the canister, a metered dose of medicamentis delivered.

Most aerosol driven inhalers are provided with some activating means fordepressing the canister. These span from simple levers pivotallyarranged in the inhaler, which levers press on the side of the canisteropposite the dispensing device, usually the bottom of the canister, tosophisticated arrangements comprising spring means acting on thecanister, which springs are activated by inhalation. A recent type ofinhaler also comprises motor means and control means together with a newtype of canister, where the canister delivers medicament as long at itis depressed, and that the control means controls the motor which actsas depressing means for the canister. For example the control meanscontrols the motor to keep the canister depressed for a certain periodof time.

Usually, the canisters and the inhalers are manufactured by separatecompanies, where the canisters have different set dimensions and certaintolerance widths, and the stroke of the dispensing device has a certainstroke. On the market there are a few different canister sizes dependingon the kind of medicament and the number of doses that each canistershall be able to deliver.

The manufacturers of inhalers have these canister measures to cope withwhen developing an inhaler, developing an inhaler for one specificcanister size. Since the general aim for the developer of the inhaler isto keep the overall size as small as possible so that the inhaler ishandy and discrete in use, the space inside the inhaler is ratherlimited. Especially when working with spring activating means it is notpossible to use long springs in order to obtain a more or less constantspring characteristics during the depression movement of the canister.Instead transmission means are used to increase the spring force actingon the canister. These transmission means are however affected bydifferences in tolerances of the canister, of the inhaler, and ofcanister and inhaler together.

If, as an example, the canister has a tolerance width of a fewmillimetres over its entire length, which is not unusual, and theinhaler has an overall tolerance width of approximately one millimetre,this could lead to a total tolerance width of the system of severalmillimetres. With such tolerance widths, either the activating meanswill have to move quite a distance before coming in contact with a smallcanister, and thus exposing the canister to sudden impacts from theactivating means, or, in the case of a large canister, that theactivating means still contains a lot of energy when the canister isdepressed. Since the starting point for the activating means varies somuch with the tolerance widths built into the system and with thelimited space available in the inhaler, it is very difficult to handlesuch differences and to design an activating means acting with the samepredictable characteristics over this span.

Inhalers for inhaing medicament into the respiratory tract comprise somesort of opening, typically also with a mouthpiece, and an air flowpassage inside the inhaler in communication with the opening. Acompartment containing medicament and dose delivering means are alsoarranged and in communication with the air passage so that, when thepatient inhales, air and medicament will mix in the air passage and willbe inhaled by the patient.

A plurality of inhalers present on the market are provided with breathactivated dose delivering means, so called breath activated inhalers.These function so as to deliver a dose of medicament when the patientinhales, i e when there is an air flow present in the air passage. Incontrast to inhalers where the patient physically has to activate thedose delivering means, e g by pressing parts of the inhaler, manoeuvringlevers and the like, the breath activated inhalers are triggered by theinhalation. This provides a more reliable dose delivery to the patientbecause the patient no longer has to time the inhalation with physicalactivation of the inhaler.

A drawback with these breath activated inhalers is unintentional oraccidental activation of the inhaler, especially by children. A childoften registers the activities of the adults and tries to do the samething as them. If for example a parent uses an inhaler to inhalemedicament, it is very likely that the child finds that interesting andwould like to do the same. If the inhaler is then left within thechild's reach it is likely that it would try to inhale. The inhalerwould then be triggered to deliver a dose of medicament which the childunintentionally could inhale. Since these medicaments sometimes arequite potent, or even lethal, there is a risk that the child will sufferfrom poisoning which could lead to serious consequences.

According to yet another aspect of this technical area, inhalers forinhaling medicament comprise a body containing a supply of medicament,an air passage and a mouthpiece in contact with the air passage,wherein, upon use, the patient puts the mouthpiece in his mouth wherebya metered dose of medicament is dispensed in the air passage and inhaledby the patient.

The mouthpiece is generally a piece of pipe, either circular in crosssection or somewhat formed to correspond to the patients mouth, that isfixedly attached to, and protrudes from, the body of the inhaler.

In order to protect the mouthpiece when the inhaler is not in use, theinhaler is arranged with a protective cover or the like. In the simplestcases, the protective cover is a kind of capsule that can be pressedover the mouthpiece and is held in place by friction or snap-fit. Adrawback with the capsule is that it is very easy to drop or loose it.

Most recent inhalers are provided with a protective cover in the form ofa lid pivotably arranged to the body of an inhaler. The lid is designedsuch that when in a protecting position, it encloses the mouthpieceprotruding from the body, and when the inhaler is to be used, the lid isswung away so as to provide free access to the mouthpiece with thisdesign the protective means can not be dropped or lost since it isattached to the inhaler.

The general problem with the above inhalers is that the mouthpiece isfixedly attached to the inhaler body, making them rather bulky. Ageneral desire from users is that the inhaler should be as small aspossible so that it could be stored away conveniently when not in use,for example in the breast pocket or the like. This is not really thecase with the present designs. Another desire from the users is that theinhaler should be easy to use in general and specifically easy and quickto activate as to inhale a dose. The activation of the inhaler may becritical if the patient suffers from a sudden reduction of therespiratory function. The inhaler must then be ready to use almost at aninstant.

BRIEF DESCRIPTION OF THE INVENTION

The purpose of the invention is to provide an inhaler, without the aboveproblems.

The primary advantage of the present invention as compared to knowninhalers is that the beginning and termination, i e activation anddeactivation, is controlled by the patient's inhalation and not thedevice, since the start of the inhalation activates the inhaler todeliver its dose and the end of the inhalation deactivates the inhaler,i e closes and refills/recharges it. This in fact increases theinhalation quality in that the end of the inhalation returns thecanister to its decompressed position, during which return the metereddose chamber is refilled. This ensures refilling/recharging of thechamber when the canister is held in a vertical position with themetered dose chamber facing downwards. It's virtually impossible to havean improper refilling/recharging of the chamber when the canister has alow level of medicament, thus ensuring that a correct fill and notpropellant gas enters the chamber. The inhaler could with the presentinvention be regarded as breath operated rather than breath activated,as with known inhalers, because both start and end of inhalationactivates the inhaler.

A general aspect of the principle function of the breath operated deviceis that it consists of two main parts movable relative to the inhalerbody. One of these is affected by an actuating or firing force from forexample a spring the first part is detachably attached to a fixed partof the inhaler, whereby the actuating force is “charged”. The secondpart acts on a medicament delivering canister and is detachably attachedto the first part. When the first part is released from the inhalerbody, due to start of inhalation, it is moved by the actuating force,whereby also the second part is moved due to the attachment to the firstpart and the canister is depressed and a dose of medicament isdelivered.

Upon end of inhalation, the second part is released whereby also thecanister is released and returns to its undepressed state.

What is obtained is thus a mechanism containing relatively fewcomponents and is capable of activating and deactivating the canister inresponse to begin and end of inhalation.

With the use of force transmission means between the activating member,such as the flap or vane, and the actuating member, such as thecompression spring capable of depressing the canister, a design with alow level of force is obtained in order to activate and deactivate thedevice. This ensures that patients with low physical capacities are ableto activate the device. This is also an advantage in connection with thenew gas propellants that due to environmental aspects are to be changedfrom CFC to HFA. The HFA propellants require a much higher force inorder to activate the canister to deliver its dose. The device accordingto the invention is able of managing these higher forces without adeteriorated or reduced functionality and handling of the inhaler by theuser as compared to known inhalers.

Further, with the invention it is possible in a convenient way tomonitor if the patient has received the medicament in an appropriateway, by including not only dosage counters but also means for measuringthe inhalation time, i.e., the time the canister has been open duringdelivery of a dose. This is easily obtained because activation anddeactivation are triggered by the inhalation. Thus a measurement of theinhalation time can then be used to evaluate if the patient has receiveda dose and has been able to inhale the dose properly into therespiratory tract.

According to another aspect of the present invention the aim of thepresent invention is to obtain a reliable, predictable and repeatableactivation of the device for delivering medicament.

This aim is solved by the present invention characterized by claim 10.

The benefit of the present invention is that repeatable and predictablehandling characteristics, like for example dose-to-dose equivalence, isobtained without the need for very fine, and thus costly, tolerancedemands on the components.

With the present invention, the dimensioning of the force requirementsis facilitated because the energy system is divided in two distinctparts, wherein the parts, when the device is non-activated, are in nophysical contact with each other. The part comprising the actuatingmeans and transmission is designed so that the actuating means may bereleased with reasonable demands on design, tolerances and the like,thus allowing a certain variation in force requirements. The other partof the energy system is designed and dimensioned such that it isactivated at a certain predetermined and repeatable force level, andthat the force available always is above the force range required forreleasing the actuating means.

Because of the division, it is not necessary to take care of thevariations through the entire system, but instead merely have tocalibrate the activating part of the system. Because this part mostlycontains rather few components, it is necessary to design and calibrateonly the activating means and the release means so that the activatingmeans is activated at a predetermined force.

When designing this part it is also only necessary to take into accountthe range within which the forces required for releasing the actuatingmeans will vary and to ensure that the force available for releasing theactuating means is substantially above this area. In this way it isensured that the device will be activated at a certain predeterminedexternal force level, and that the activation ensures a release of theactuating means.

It is a further object of the present invention to provide a device forthe above mentioned type of inhalers which reduces the risk ofunintentional triggering of the inhaler.

With a device according to the invention, the movement means, such asfor example a plate or a flap, or a member of the movement means, suchas a pivotally arranged linkage, or combinations of several pivotablyarranged members, is held substantially stationary when the inhaler issubjected to sudden movements, but is activated, or moved, duringinhalation. This prevents unintentional activation of the inhalerbecause of forces acting on, and trying to pivot, a member of themovement means.

Preferably the member of the movement means is balanced as regards toforces exerted on the inhaler so that the point of momentum of themember is arranged at or near its pivoting axis. This will prevent themember from being pivoted because of acceleration or retardation. With adevice according to the invention, external forces on the inhaler willnot trigger the breath-activated device as easily as with known inhalersof this type when the inhaler is in a ready-to-use state.

In one embodiment, when the member of the movement means is designed asa pivotable plate-like flap, a balancing means which has a momentsubstantially equal to the moment of the flap is arranged on theopposite side of the pivoting point. The balancing means then balancesthe flap so that it is held stationary when the inhaler is subject toexternal forces in a very simple but yet effective way

Yet a further aim of the present invention is to allow for an inhaler toaccommodate for differences in tolerance widths of containers withmedicament and provide a reliable function and predictable dose-to-doseequivalence of the doses delivered. Preferably the inhaler can alsoaccommodate for different container sizes.

With a device according to the invention the function of the inhaler isno longer influenced by the tolerance width variations of container andinhaler, which means that predictable dose-to-dose equivalence isobtained.

Further it increases the robustness and simplifies the design of theinhaler, in particular the activating means for delivering doses, sincethis no longer has to be over-dimensioned, such as springs, levers,attachments and the like, as the activating means no longer has to dealwith the problem of tolerance variations.

Also a further aim of the present invention is to avoid the abovementioned problems concerning unintentional/accidental activation ofbreath activated inhalers.

The advantage of the invention over prior art is that when the safetymeans is not operated, any unintentional inhalation through the inhalerwill not affect the activating means. Since the activating means istriggered by the air flow through the inhaler during inhalation, amanipulation of this air flow preventing the activating means to beunintentionally activated provides an easy and reliable safety device.

The blocking of the auxiliary air passage may be obtained in manydifferent ways, for example by the finger or hand of the user, by flapsor lids or the like.

Preferably, the openings are arranged such on the inhaler, and/or havesuch sizes, that only an adult is able of blocking the openings in orderto activate the activating means upon inhalation.

It is to be noted that the present invention may be used with all breathactivated or breath controlled inhalers, regardless of type ofmedicament.

According to a further aspect of the invention, the purpose of thepresent invention is to provide a mouthpiece without the above problems.

With a device according to the invention, several advantages areobtained. Due to that the mouthpiece is arranged inside the inhaler bodywhen not in use, the size of the inhaler can be made smaller, and also amuch smoother shape can be obtained since there are no protruding parts.When the inhaler is to be used, it is activated whereby the mouthpieceis moved somewhat outside the body so as to enable the user to inhalethrough it.

Preferably the inhaler comprises a protective cover which protects themouthpiece when not in use, and keeps the mouthpiece in place.Preferably also, the mouthpiece is arranged with means for releasablyholding the mouthpiece in place in the activated position in awell-defined position relative the body.

When the protective cover/lid is arranged to an activating means, whichsets the inhaler ready for a subsequent dose, by refilling dosecompartments and placing the activating mechanism of the inhaler in aready state, the inhaler is “charged” after a dose has been delivered tothe patient. This means that the inhaler is ready to use instantlywithout any further actions than to open the inhaler, which is ofimportance during critical medicating.

Further aspects of and advantages with the present invention will becomeapparent from the detailed description of embodiments of the inventionand from the patent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following description of several embodiments of the invention,reference will be made to the drawings, of which:

FIGS. 1-4 show schematically the basic function of an actuatingmechanism assembly comprised in the present invention,

FIGS. 5-7 show different variants of the basic function according toFIGS. 1-4,

FIG. 8 shows a side view of the upper part of an inhaler comprising adevice according to a first feature of the invention,

FIG. 9 is a cross section taken along the line IX-IX of FIG. 8,

FIG. 10 is a view similar to FIG. 9 but not in cross section and with ahousing removed.

FIG. 11 shows a cross section taken along line XI-XI of FIG. 10,

FIG. 12 is a perspective view of the device according to the invention,

FIG. 13 is a similar view as in FIG. 12 but rotated 90°,

FIG. 14 shows an example of a second feature of the present invention aside view in cross section of an inhaler comprising the presentinvention, and

FIG. 15 shows a detailed view of a transmission and locking meanscomprised in the invention,

FIG. 16 shows a cross sectional view taken along line XVI-XVI of FIG. 15

FIG. 17 shows a side view in cross section of an inhaler comprising athird feature of the present invention,

FIG. 18 shows a detailed perspective view, partly cut away, of abreath-activated component according to the invention balanced in twoaxes and comprised in the inhaler of FIG. 17,

FIG. 19 shows the component of FIG. 18 from the side,

FIG. 20 shows a detailed perspective view of a flap comprised in aninhaler, balanced in one axis,

FIG. 21 shows a plan view of the flap of FIG. 20,

FIG. 22 shows a side view of the flap of FIG. 20,

FIG. 23 shows a detailed view of another use of the present invention,

FIG. 24 shows a detailed view of a further use of the present invention.

FIG. 25 is a detailed view of a part of an inhaler comprising the deviceaccording to a fourth feature of the present invention in a non-activeposition,

FIG. 26 is the same view as FIG. 25 with the device in an activeposition, and

FIG. 27 is the same view as FIG. 25 with the device in another activeposition.

FIG. 28 shows a side view in cross-section of an inhaler foraerosol-driven medicament with a device according to a fifth feature ofthe invention,

FIG. 29 shows a part view in cross-section of an inhaler for powdermedicament with a device according to the fifth feature of theinvention.

FIG. 30 is a detailed view of a part of an inhaler in cross-section witha first embodiment of a sixth feature of the invention,

FIG. 31 is a detailed view of a part of an inhaler in cross-section witha second embodiment of the sixth feature of the invention,

FIG. 32-35 shows the function of the first embodiment,

FIG. 36-38 shows the function of the second embodiment,

FIG. 39 shows an example in connection with an inhaler for aerosoldriven fluid medicaments, and

FIG. 40 shows a example of a mouthpiece according to the invention and aspray head as a unit.

DETAILED DESCRIPTION OF THE INVENTION

The different features of the present invention will be described indetail and with reference to the drawings. In connection to the detaileddescription, use is made of “vertical” and “horizontal” to definedirections of different components. It is to be understood that thesedirections refer to a position of the inhaler when it is used, to definethe relationships between components of the embodiment described, andshould not be regarded as limiting the invention.

The general principle and function of the breath operated deviceaccording to the first aspect of the invention is shown schematically inFIGS. 1-4. Here one part F is fixed in relation to the inhaler. In factit could for example be the inhaler housing or the like. A second part,hereafter named shuttle S is movable in relation to the fixed part F.Further, an actuating or firing force AF, from for example a spring, isacting on the shuttle S. When the inhaler is in a ready to use state,FIG. 1, the actuating force is “charged” and the shuttle is held in thecharged position in relation to the fixed part by a first movablelocking means LM1. A third part, hereafter named canister actuator, CAis also movable in relation to the fixed part F and releasably attachedto the shuttle S by a second movable locking means LM2. The canisteractuator is arranged so that it is connected to the bottom of a canisterC, which canister C in an inhaler is arranged so that its bottom isfacing upwards and that its other end is provided with a valve assembly,which assembly is known per se. The canister C is pushed upwards in thefigures by a spring of the canister valve assembly, causing a canisterforce CF.

When the inhaler is activated, in which a patient inhales, the firstlocking means LM1 is moved out of engagement with the fixed part Fwhereby the actuating force AF forces the shuttle S downwards, FIG. 2.Because the canister actuator CA is locked to the shuttle S by thesecond locking means LM2 it is also pushed downwards against the forceCF of the canister valve assembly, thereby depressing the canister sothat a metered dose of medicament is delivered.

When the patient terminates inhalation, the second locking means LM2 isactivated and releases the canister actuator CA, whereby the canisterreturns to its undepressed state and subsequently moves the canisteractuator upwards.

When the inhaler is to be charged and ready for use, the shuttle S ismoved upwards, for example by the patient, whereby the two locking meansLM1, LM2 engage and hold the device in its ready-to-use state.

It is to be understood that the locking means may be arranged indifferent ways in order to obtain the desired function between theparts. FIGS. 5-7 show different arrangements. Thus the locking meanscould be arranged as pulling or pushing elements in order to achieve thedesired function. The different elements could for example be designedas shuttles, tubular elements arranged inside each other and the like.Further, since the inhaler is breath operated, there are requirementsthat the forces needed to release the locking means are quite low inorder to ensure that even patients with weak respiratory capacities arecapable of activating the inhaler and receiving a dose of medicament. Inthat respect, the device is arranged with force transmission means whichenable a relatively low force to release the locking means, which inturn hold a rather strong actuating means. Examples of such forcetransmission means are described below.

An example of an inhaling device according present invention inconnection to the first feature is shown in the FIGS. 8-13. The inhalingdevice 10 is arranged in an inhaler, comprising a housing, in theembodiment shown in two detachable parts, where the upper part is shownin FIGS. 8-9. The upper part is arranged with a holder/chamber 18 for ametered dose aerosol container 20, hereafter named canister.

The canister, known per se and not shown for clarity, contains themedicament. It is further provided with a valve assembly in the canistercomprising a valve stem, which normally is urged downwardly by acompressed spring. The valve assembly further includes a smallcompartment or chamber in the canister, which chamber defines themetered dose to be inhaled. The valve stem is provided with in- andoutlets for filling the metered dose chamber with medicament anddelivering the metered dose depending on the position of the stem in thevalve assembly, as will be described in detail below.

The lower end of the valve stem is attached to, and supported by, anozzle, which in turn is in communication with a mouthpiece. An air flowpassage, not shown, is arranged from an opening on the top of thehousing to the mouthpiece arranged on the housing near the nozzle.

To the upper part of the canister, an actuating means, hereafter namedpressure plate 34, is arranged, abutting the bottom of the canister. Thepressure plate is arranged to a cylindrical body 36 movably arranged inthe vertical direction around a support shaft 37. The lower part of thecylindrical body is arranged with an inwardly projecting ledge 38. Acompression spring (not shown) is arranged around the support shaftbetween the ledge and a fixed upper abutment 40.

The inhaler further comprises an actuator mechanism assembly. Itcomprises a flap 42 or vane, FIG. 9, pivotably arranged in a passage 43in the inhaler. As shown in FIGS. 12 and 13, a first arm 44, pivotablyis arranged with its upper end to a cylindrical shuttle 46. The arm 44rests with its lower end on the flap or vane adjacent its pivoting point47, FIG. 9. The shuttle is movably arranged around the cylindrical body,whereby the upper part of the shuttle is engaging a projection 48 on theouter surface of the cylindrical body. On the first shuttle tworotatable holding means 50 are arranged, FIG. 13. Between these a firstfork like member 52 is arranged. The fork-like member 52 is arrangedwith recesses 53 for receiving the holding means, as will be explainedbelow. A pin 54 protruding from the cylindrical body, FIG. 11, is heldbetween the forks of the fork-like member.

The shuttle is further provided with a second arm 56, arranged parallelto the first arm. The second arm is shorter than the first arm, thereason of which will be explained below.

On the opposite side of the shuttle a second set of rotatable holdingmembers 58 are arranged, FIG. 12. Between these a fork-like member 60 isarranged, which is attached to the cylindrical body. The fork-likemember has projections 62 on which the holding means rest and therebyholds the fork-like member in position. Between the forks of thefork-like member a protrusion 64 is arranged, which is attached to thepressure plate 34. Some distance downwards on the fork-like member,recesses 66 are cut out.

The function of the device is as follows. The metered dose chamber isfilled with medicament in a known fashion. The shuttle has been pushedupwards by a return means so that the first arm 44 rests on the flap orvane 42. The return means comprises an arm 70 extending downwards, andconnected to for example a protective cover for a mouthpiece. The upperpart of the return means is designed as a ring 72 surrounding thecylindrical body 36. Between the ring and the shuttle a spring isarranged (not shown). Preferably the return means is activated when thecover is closed after use, thus activating the inhaler before thesubsequent use.

When a user begins to inhale through the mouthpiece, the flap 42,arranged in the air conduit adjacent the air intake, is pivoted inwardsby the pressure difference created on both sides of the flap. Due to thepivoting movement, the first arm 44 is pushed off the resting positionon the flap or vane. This causes the shuttle 46 to move downwards,whereby the rotatable holding means 50 also are moved downwards untilthey reach the recesses 53. This enables the forks of the fork likemember 52 to move away from each other thereby releasing the pin 54 andthus the cylindrical body. The compression spring acting on the ledge 38on the inner surface of the cylindrical body moves it and the pressureplate 34 downwards, thereby depressing the canister. Because the stem ofthe canister is attached to the stationary nozzle, the stem is pushedinto the metered dose chamber of the canister, thereby opening theconnection between the dose chamber and the nozzle. The metered dose isdelivered through the nozzle and is nixed with the suction air andenters the respiratory tract of the patient.

The downward movement of the shuttle causes the second arm 56 to engagewith the flap or vane and rest there. When the patient terminates theinhalation, the flap or vane is pivoted back to its original position.The pivoting movement causes the second arm to leave the rest positionon the flap or vane, whereby the shuttle is moved downwards further. Thesecond set of rotatable holding means 58 are also moved downwards,thereby permitting the forks of the second fork like member 60 to moveaway from each other and release the pin 64 of the pressure plate, thusalso releasing the pressure plate 34, so that the canister is returnedto its undepressed by the spring of the valve assembly and thecommunication between the metered dose chamber and the nozzle is closed.

During the return movement from depressed to undepressed position of thecanister, the metered dose chamber is refilled and ready for the nextdose. It is to be noted that the refilling of he metered dose chamberalways is done when the inhaler and canister are held vertically, thusensuring refilling of the metered dose chamber with medicament, evenwhen small amounts of medicament remain in the canister.

The inhaler could also be provided with detection and monitoring meansproviding information regarding the inhalation. These normally comprisecounters for displaying the number of doses delivered or the number ofdoses that remain. With the device according to the invention, detectionmeans for detecting the inhalation period may also be included becauseboth the beginning and end of inhalation activates the device. Theinhalation period is then an indication of the inhalation quality in thesense that if the device registers that a rather short inhalation hasbeen done, this is an indication that the patient has not inhaled themedicament into the respiratory tract properly. The inhaler could thenindicate to the user, to make him aware of this, and to suggest anotherdose.

The measuring points for the detection means could be any of the movingpart of the device of the invention, such as the flap, the shuttles, thepressure means, and so forth.

It is to be understood that the invention is not limited to theembodiment described and shown on the drawings but may be altered withinthe scope of the claims.

For example, the different springs acting in the device may havedifferent configuration and/or attachment points in order to obtain thesame function. For example, the pressure means may be a vacuum bellows,known per se.

It is further conceivable to have other return means than a protectivecover, like for example a button, a sleeve, lever or the like of anykind and placement. For example the upper part of the housing may beslidable in respect to the lower part in a vertical direction foractivating the return means in the described way.

The second feature of the invention will now be described in connectionwith drawings 14-16. FIG. 14 shows an example of an inhaler comprisingthe present invention. The inhaler 210 shown is intended foraerosol-driven medicament contained in a canister 212 arranged insidethe housing 214 of the inhaler. A stem 216 of the canister is seated ina nozzle 218 provided with an outlet directed towards an inhalationmouthpiece 220.

The inhaler is further provided with breath-activating means, whichcomprises a flap or vane 222 pivotably arranged adjacent an air intake224 and substantially covering the intake when non-activated. The flapor vane is arranged with a protrusion 226 adjacent its pivoting point228. A release means is arranged to the activating means, comprising anarm 230 which is arranged with a hook 232 at its upper end, which hookgrips a ledge 234, in turn arranged close to the protrusion. Acompression spring 236 is arranged between the arm and the housing ofthe inhaler. The arm extends downward into a transmission and lockingmeans 248.

A pressure arm 244 is arranged in contact with the top of the canisteras seen in the figure and pivotable around a pivoting point 246 fixed tothe housing.

The transmission and locking means 48, FIGS. 15 and 16, comprises afirst pivoting locking member 250, pivotable around an axis 252, whichaxis is fixedly attached to a stationary plate 253, partly taken away inFIG. 15 for clarity. The locking means is arranged with a surface 254inclined with respect to a vertical axis as seen in FIG. 15. The lowerend of the arm 230 is arranged with a mating inclined surface 256. Thelocking member is provided with an upwards facing ledge 258, on whichledge a first transmission member 260, pivotable around an axis 261,rests with a recess 262, thus holding the first transmission member in asubstantially horizontal position. The axis 261 is also fixedly attachedto the plate 253. A second transmission member 264, arranged pivotablyaround an axis 266 in a vertical direction rests with a lower end on thesecond transmission member. The second transmission member is arrangedwith an arm 267 whose outer end is bent inwards in FIG. 11.

The upward facing surface 269 of the arm mates with a ledge arranged ina grove 271 of a movable plate 268. The shaft 266 of the secondtransmission member is also attached to the plate 253. A shuttle 276 isattached to the movable plate 268 via attachments 275. The lower end ofthe movable plate 268 is arranged with a ledge 270. Between this ledge270 and a ledge 272 of the stationary plate 253 are arranged twocompression springs 274. An arm 276 is attached to the shuttle 268. Atthe upper end of the arm 276 a hook 278 is arranged. The hook grips thefree end of the pressure arm 244. The transmission and locking meansalso comprises suitable guide means for the different components, notshown.

The function is as follows. When a patient inhales through themouthpiece 220, a pressure difference is created between the interior ofthe inhaler and the outside, and thus a pressure difference over theflap or vane 222. The pressure difference causes the flap or vane topivot around its pivoting point 228. The pivoting movement causes theprotrusion 226 to push the hook 232 of the arm 230 off the ledge 234whereby it is forced downwards by the compression spring 236. The gapbetween the arm 230 and the locking member 250 provides an accelerationof the arm and thus a certain dynamical force. This force provides anadditional feature and advantage in designing the system and therequirements for releasing the locking member.

The downward movement of the arm 230 of the release means, due to thespring 236, causes it to come in contact with its inclined surface 256against the inclined surface 254 of the locking member 250. The movementand the inclined surfaces causes the locking member to pivot clockwisein FIG. 15 whereby the ledge 258 of the locking member is pushed out ofcontact with the recess 262 of the first transmission member 260. Thefirst transmission member is thereby free to turn downwards, whereby thearm 267 of the second transmission member 264 is moved out of contactwith the recess of the groove 271. This frees the movable plate 268,which is pushed downwards due to the force of the compression springs274, whereby the shuttle 276 is also moved downwards due to beingattached to the movable plate 268 via the attachments 275. The force ofcompression springs is transmitted to the canister 212 via the pressurearm 244 and the canister is depressed.

As can be seen in FIG. 15, the connection between on the one hand theflap 222 and arm 230, the activating means, and on the other hand thelocking and transmission means 248, transmitting the movement andactuating the delivery of the dose, the so called actuating means, isbroken in that there is a gap between the arm 230 and the locking member250. It is thus much easier to design and balance the activating meansso that it is activated due to a predetermined pressure difference overthe flap, and to design the compression spring 236 so that the force bythe arm always is above a certain force required to trigger the rest ofthe system.

It is to be understood that the connection between the activating meansand the actuating means is not dependent on an actual gap between theparts, as shown in the Figures. The parts may well be contacting eachother. The main importance is that the operation of the activating meansis influenced as little as possible by the actuating means and that itis ensured that the activating means always is capable of activating theactuating means upon inhalation. This approach enables to design thesystem so that care is taken of the differences in the properties of allcomponents of the transmission and actuating means in order to have areliable, predictable and repeatable activation of the inhaler.

In respect of the transmission described above, there could be more orfewer transmission members present depending on the forces available fortriggering or unlocking the device and/or forces to be released. In thisrespect the transmission may also be of any mechanism capable oftransferring a movement and capable of enabling a low force to release ahigh force.

Even though the present invention has been described in connection withan aerosol inhaler, it is to be understood that it is equally applicableto other types of inhalers such as powder and nebulisers, as well as fornasal inhalers.

Several devices of the present invention may be used in the same medicaldistributor in sequence, dependent, or independent, of each other. Withdependent is meant that one component is moved to an end position andthereby triggers a subsequent component. With independent is meant thatone component is moved to an end position. The subsequent triggering isthen performed by external activation.

For example in the above example, a return means could also be providedwith the same function as the above described device. This couldcomprise a second locking and transmission means replacing theattachments 275 between the movable plate and the shuttle 276. Itcomprises a further arm, which, upon termination of inhalation, isreleased by the flap or vane, whereby it moves the second locking meansout of locking position. This causes the shuttle 276 to be released fromthe movable plate 268, whereby the canister is returned to itsnon-depressed state by the spring arranged in the canister. Return meansarranged to the movable plate 268 will push it upwards to the initialposition, which for example may be done manually by shutting a hygienelid or pushing a button.

As for injectors of the above described type, several devices accordingto the present invention may also be used in one injector. For instanceone may be associated with the triggering of needle penetration, whichis often done by pushing the syringe forward in the housing of theinjector. When the syringe is in the forward position, this triggers theemptying of the syringe. This is done by springs pushing the plungerinto the syringe. When the plunger has reached the dose end position orbottom and the dose is delivered, this triggers a needle retraction or aneedle protection to be pushed forward. There could thus be a series ofcomponents or transmissions acting in sequence, where each sequencecould make use of the “broken connection” according to the invention.With the present invention there is thus easier to take into account anddeal with variations in the characteristics of the components in thechain when calculating the forces required for the reliable function ofthe device.

In the description both force and energy have been used in describingthe present invention. It is to be understood that are equallyapplicable. For example releasing the locking means, a certain force maybe applied to the locking means in order to move it out of lockingposition. In the same context, a certain energy may also applied, whichfor example may comprise the dynamical energy obtained by the movingrelease means.

It is to be understood that the embodiments described above and shown inthe drawings are non-limiting examples of the present invention and thatit is defined by the scope of protection of the patent claims.

The third feature of the present invention will now be described inconnection with the drawings 17-24. FIG. 17 shows an example of aninhaler comprising the present invention. The inhaler 300 shown isintended for aersol-driven medicament contained in a canister 302arranged inside the housing 304 of the inhaler. A stem 306 of thecanister is seated in a nozzle 308 provided with an outlet directedtoward an inhalation mouthpiece 310. Pressure means 312 is arranged incontact with the top of the canister as seen in the figure. The pressuremeans comprises a piston 314 and a pressure plate 316. Compressionsprings 318 are arranged between the pressure plate and the housing.Actuating means 320 are arranged in connection with the pressure platefor holding it in a position where the compression springs aretensioned. The actuating means further comprise levers and shuttles.

FIG. 18 shows a detail of a component 322 of a breath-activated inhaler.The component comprises an air intake passage 324, through whichairflows during inhalation. In the air intake a flap or vane 326 isarranged pivotably around a pivot axis 328. Spring means (not shown)urges the pivot upwards in FIG. 18 against the interior wall of the airintake. In this position the flap or vane substantially blocks the airintake passage. The part of the vane opposite the pivoting axis isconnected to the actuating means 320.

The general function of the component is that during inhalation, apressure difference is created between the interior and the exterior ofthe inhaler housing 304. This pressure difference causes the flap orvane 326 to pivot around the pivoting axis 328 against its spring meansso that the air intake opens and an air flow is created. The pivotingmovement of the flap or vane triggers the actuating means so that thehold of the pressure plate 316 is released whereby the springs 318depresses the canister 302. In turn the stem 306 is pushed into thecanister whereby a dose of medicament is delivered through themouthpiece 310.

The flap or vane is arranged with balancing means 332. In the embodimentshown in FIGS. 18 and 19 it comprises a weight arranged on the oppositeside of the pivoting point in relation to the flap or vane. The centreof mass 334 of the weight is arranged in the same plane as the centre ofmass 336 of the flap or vane and the pivoting point. The weight of thebalancing means is chosen such that the weight times the distance to thepivoting point equals the weight of the flap or vane times the distancebetween its centre of weight and the pivoting point. With thisarrangement the flap or vane is balanced as regards external forcesexerted on the inhaler in that the resulting moment on both sides of thepivoting point is the same. Since the centres of mass are placed in thesame plane as the pivoting point the flap or vane will be balanced forexternal forces in all directions.

FIGS. 20-22 show an embodiment where the flap or vane 326 is notbalanced in all directions. Here the weight 332 is placed somewhat belowthe pivoting point and the flap or vane. Here the centres of mass 336 ofthe flap or vane and the balancing means 334 and the pivoting point 16Will not be arranged in the same plane. Here the flap or vane will besubstantially balanced along the line 338 intersecting the pivotingpoint and the resulting centre of mass.

This configuration may be due to the limited space available in theinhaler. The resulting centre of mass 336 will thus not coincide withthe pivoting point of the flap or vane but with the line 338. It ishowever arranged such that the flap or vane is balanced for forcesexerted on the inhaler in selected directions. For example with anaerosol inhaler it is recommended that it is shaken before use so thatthe medicament inside the canister is properly suspended. Depending ondesign of the inhaler, i. e. how it is held, it is shaken in certaindirections. The inhaler shown in FIG. 17 will be shaken substantially inthe vertical direction as shown by arrows 330. The flap or vane is thensubstantially balanced with respect to those directions.

FIG. 23 shows another use of the present invention. For many inhalers itis important that the inhalation forces are kept low, making itnecessary to have the actuating means respond to these low forces. Onthe other hand the depression forces need to be rather high in order tobe capable of overcoming the forces for depressing the canister.Therefore, it is necessary with some kind of transmission mechanismwhich amplifies the movement from the flap or vane to the compressionsprings. FIG. 23 shows one example of how the first link of thetransmission comprises a lever 350 pivotably arranged.

The lever is connected to the flap or vane 326 via a piston 352. Asecond arm 354 or lever is connected to the lever via a ledge 356. Thetransmission 358 comprises further arms, levers, pistons, shuttles andthe like in order to transmit and transfer the movement to a holdingmeans 360 holding the pressure plate 316 against the force of thecompression springs 318. When a patient inhales, the flap 326 is pivotedaround its pivoting axis whereby the piston 352 is pushed downwards. Thepiston pivots the lever 350 whereby the arm 354 disconnects from theledge. The movement is transferred through the transmission until theholding means 360 releases the pressure plate. Because very small forcesare needed, and desired, in order to pivot the lever, it is balancedagainst external forces according to the invention. A weight 162 isarranged on the opposite side of the pivoting point and chosen such thatthe resulting centre of mass of the weight an the lever coincides withthe pivoting point 364, whereby the lever is balanced against directedforces, for example vertically as seen in FIG. 23.

FIG. 24 shows a detailed view of a locking and release means 366 for abreath activated inhaler. It comprises a first pivoting member 368pivotable around an axis. The first member is arranged with a surface370 inclined with respect to a vertical axis. The lower end of an arm372 arranged to a breath activated member, not shown, is arranged with amating inclined surface 374. The first member is provided with anupwards facing ledge 376, on which ledge a second pivotable member 378rests with a recess 380, thus holding the second member in asubstantially horizontal position. A third member 382, arranged slidablyin a vertical direction rests with a lower end on the second member. Thethird member is attached to a holding member, which holds for examplepressure springs arranged to a canister of an inhaler in an energised,tensioned state. As soon as the arm 372 is moved downward, whereby thesubsequent members are brought out of contact with each other, thecanister is depressed by the force of the springs. In order for theinhaler not to be activated by sudden forces, the first member 368 isbalanced so that its centre of mass is placed in the pivoting point ofthe member.

Even though the present invention has been described in connection withan aerosol inhaler, it is to be understood that it is equally applicableto other types of inhalers such as powder and nebulisers, as well as fornasal inhalers working with the same principles.

It is to be understood that the present invention may be used forbalancing statical as well as dynamical forces, i e predetermineddirections of movement, non-predetermined directions of movement as wellas movements in several planes.

Even though the invention has been explained in connection with abalancing means arranged to the flap and lever of the transmissionmechanism, it is to be understood that the principles of the inventionmay be utilised for other components of an inhaler which are pivotablyarranged.

In this context it is to be understood that the wording “pivotably” maybe members balancing on an edge, or that the shaft on which a pivotingmember is arranged is smaller than the hole, so that there is onespecific contact point, pivoting point, between the shaft and the hole.

The fourth feature of the present invention will now be described inconnection with FIGS. 25-27. In the drawings parts of an inhaler foraerosol driven medicament with breath-activated dose-delivering means isshown. The medicament and the aerosol as propellant are stored in acanister 410 where the upper part is shown in the drawings.

In a conventional manner, the canister is arranged with a stemcontaining a passage at its lower part. The stem protrudes inside thecanister, and when the canister is depressed a dose of medicament isdelivered through the passage of the stem. Also in a conventionalmanner, the stem communicates with an inhalation opening, through whichthe dose is delivered. These parts are not relevant to the invention andare therefor not shown for the sake of clarity.

A depressing means is arranged at the upper part of the canister. In theembodiment shown it comprises a pivotally arranged lever 412 with aportion that is curved downwards somewhat corresponding to the concaveshape of the canister end wall. At the opposite end to the pivotingpoint 414 of the lever, a depression means is arranged, comprising acompression spring (not shown) attached via an arm 16 to the end of thelever.

Above the spring means, an activating means is arranged comprising aflap 426 pivotally arranged in the inhaler in an air passage 428communicating with the exterior of the inhaler. The shape of the flapand the passage is such that the flap substantially closes the passagewhen it is in its uppermost position, FIG. 25. The flap is connected tothe depression means.

When a patient inhales in order to receive a dose of medicament, theinhalation causes a pressure difference between the interior of theinhaler and the exterior. This pressure difference causes the flap 246to pivot and the passage 428 to open so that an air flow is created. Thepivoting movement of the flap acts on the depression means so that thecompression spring pulls the arm 416 downwards whereby the lever 412 ispivoted downwards. The pivoting force depresses the canister 410 so thata dose of medicament is delivered.

An adjustment means 440 according to the invention is also arranged inthe inhaler. It comprises a generally L-shaped member 442 arranged in acompartment 444 and movable in a vertical direction. The lower branch ofthe L-shaped member protrudes somewhat over the end wall of thecanister. The lever 412 is pivotally arranged to the lower branch of theL-shaped member adjacent the intersection point with the upper branch. Avertically acting compression spring 446 is arranged between the inhalerhousing and the lower branch of the L-shaped member, where the contactpoint 448 of the spring is somewhat closer to the canister than thepivoting point 414 of the lever. The upper branch of the L-shaped memberis provided with a number of teeth 450 arranged on the surface facinginwards. The opposite surface of the compartment is provided with anumber of corresponding teeth 452.

When a canister is inserted in the inhaler, the end wall will come incontact with the lower branch of the L-shaped member 442, therebypushing it upwards somewhat against the force of the compression spring446. Because the contact point 454 between the L-shaped member and thecanister is further out on the lower branch of the L-shaped member thanthe contact point 448 of the compression spring, the L-shaped memberwill be tilted somewhat outwards in FIG. 25 when the member is movedupwards by the insertion of the canister. Because of the tilting, theteeth of the upper branch and the compartment are not in contact witheach other, FIG. 25.

When the lever is activated upon inhalation, the upwards directedreaction force on the lever at its pivoting point 414 will cause theL-shaped member to pivot around the contact point 448 of the compressionspring and the teeth of the upper branch of the L-shaped member and theteeth of the compartment to engage with each other, thereby fixating thevertical position of the member and in turn the position of the pivotingpoint of the lever, FIG. 26. The adjusting of the pivoting point of thelever by using the end of the canister as a “reference points” ensures aconstant and reliable relation between the two with more or less thesame angle of the lever in relation to the canister end wall, regardlessof differences in tolerances of the different components, i e thecanister, the inhaler or both, FIG. 27. With the device according to theinvention variations in the order of 10-20% of the length of the levercan readily be handled.

It is to be understood that although the adjusting member is shown withan L-shape where the branch with teeth is facing upwards, this membercould be facing downwards with the teeth on the other side of the branchand corresponding teeth on an opposite surface. Further, otherconfigurations of the member are conceivable for obtaining the samefunction of the height adjustment. Also fixating means other than teethcould be used.

In this context it is conceivable to have an adjusting means with thesame function, and also using the end wall of the canister as areference together with the spring means. If the spring means also isadjustable in height, the adjustment span could accommodate forcanisters with larger differences in size than tolerance differences.

A fifth feature of the present invention will now be described inconnection with FIGS. 28-29. FIG. 28 shows, as an example, an inhalerfor aerosol driven medicament which may utilise the present invention.The inhaler comprises a housing 510 with an opening 512 intended forinhalation of a dose of medicament. Inside the housing is arranged acanister 514 containing the medicament and aerosol as propellant. Thecanister is provided with dose delivery mechanism comprising aspring-loaded stem 516. The stem is provided with a passage extendinginto the canister. The stem/lower part of the canister is supported by aholding/fixating device 518.

At the opposite end of the canister stem, an activating means 520 isarranged. It comprises in the embodiment shown a spring 522 with one endpressing on the canister and the other end supported by a holder 524.

The activating means further comprises an air inlet 526 arranged in theinhaler housing and a flap 528 pivotally arranged adjacent the airintake. When the flap is in a resting, inactivated, position, it coversthe air intake. Arranged in contact with the flap is a holding means530, which in the embodiment shown comprises an elongated arm extendingalongside the canister side. The arm is at its lower end arranged with aledge 532. When in a resting position, the arm and the ledge holds thecanister in an inactivated position against the force of the spring. Theinterior of the inhaler, from the inhalation opening to the air intakeforms an air passage.

The inhaler further comprises a safety means. It comprises at least oneauxiliary air intake 534 arranged to communicate with the inhaler airpassage, forming an auxiliary air passage with the inhalation opening,where the intake is positioned between the inhalation opening and theflap/main air intake. Further auxiliary air intakes 536 are shown withbroken lines.

In normal use of the inhaler, without the safety means, the start of aninhalation through the inhalation opening causes a pressure differencebetween the interior and the exterior of the inhaler. This pressuredifference causes the flap to pivot, thereby causing an air flow throughthe inhaler from the air intake to the inhalation opening. The pivotingmovement of the flap acts on the elongated arm so that the arm is swungaway somewhat from the canister. This causes the ledge to release thecanister from its inactivated position. The force of the spring causesthe canister to depress whereby the stem is pressed into the canisterand a dose is delivered to the inhalation opening, which dose is inhaledby the patient.

When the safety device according to the invention is used with theinhaler and the auxiliary air intake is closed, the function is asdescribed above.

If on the other hand someone tries to inhale without closing theauxiliary air intake, an air flow passage is created from the auxiliaryair intake to the inhalation opening thereby preventing a build-up of apressure difference inside the inhaler. Because no pressure differenceis created, the flap will not be affected by the inhalation.

FIG. 29 shows another example of an inhaler where the present inventionis utilised. The inhaler shown is intended for medicament in powderform. The inhaler comprises a housing 540. At one end of the housing amouthpiece 542 with an inhalation opening 544 is arranged. Themouthpiece can be protected by a protective cover 546.

Arranged inside the opening is a means for enabling access tomedicament. The means comprises an elongated body 548 with a passagethrough its length, hereafter named outlet passage. One end 550, the onefacing inwards, is arranged with sharpened edges. The elongated body isslidably supported in a hole in the opening, whereby the other end ofthe elongated body is arranged in the opening. An activating means isarranged to the elongated body, comprising an air intake 552, a flap 554pivotally arranged adjacent the air intake and a mechanism 556 designedto be able of moving the elongated body inwards when the flap is opened.

Further inside the inhaler and the elongated body a wheel 558 isrotatably arranged. The wheel is arranged with a plurality of recesses560 and means for rotating the wheel to different positions.

The medicament is packaged in blisters, where each blister enclosurecontains one dose of medicament. The blister enclosures are placed inthe recesses.

The inhaler further comprises a safety means. It comprises at least oneauxiliary air intake 580 arranged to communicate with the inhalerinterior, forming an auxiliary air passage with the inhalation opening.

During normal use, without the device according to the invention, theinhalation causes a pressure difference between the interior and theexterior of the inhaler. This pressure difference causes the flap 554 toopen and an air flow to be created through the air intake 552 and thepassage of the elongated body 548. The movement of the flap causes theactivating means to move the elongated body forward so that its pointedend penetrates the blister enclosure whereby a passage between theinterior of the enclosure and the inhalation opening is created so thatmedicament is inhaled.

When the safety device according to the invention is used with theinhaler and the auxiliary air intake 580 is closed, the function is asdescribed above.

If on the other hand someone tries to inhale without closing theauxilary air intake, an air flow passage is created from the auxiliaryair intake 580 through passage of the elongated body to the inhalationopening, thereby preventing a build up of a pressure difference insidethe inhaler. Because no pressure difference is created, the flap willnot be affected by the inhalation.

In this context it is to be understood that the auxiliary air intake maybe closed or blocked by the fingers of the patient or by a mechanicalmeans. Since the greatest risk of unintentional inhalation is fromchildren, the air intakes should preferably be placed so that a childcannot close the auxiliary intake without great effort.

There are several ways of obtaining this. One way is that the size ofthe auxiliary air intake is such that a child's finger cannot block it.Another way is that there are several auxiliary air intakes arranged inthe inhaler housing so that it is difficult for a child to place severalfingers over all of the intakes. Further the distance between theintakes could be such that it is impossible for a child's hand to reachall the intakes.

If the medicament is of a very potent toxic, or even lethal kind, ifinhaled wrongly, the device could be designed such, and with theauxiliary air intakes positioned such that both hands are needed inorder to cover or block all intakes.

In this context it is to be noted that, if more than one auxiliary airintake is used, the activating means is arranged such that it is onlyactivated when a pressure drop corresponding to a complete blocking ofall intakes is reached, i e it shall not be sufficient to block some ofthe auxiliary air intakes in order to activate the inhaler. By providingdifferent number of openings and by arranging these with differentconfigurations, different “levels of security” may be obtained with thepresent invention.

A sixth feature of the present invention will now be described inconnection with FIGS. 30-40. An inhaler 610 comprising a device 611according to the invention consists of a body 612, where only the lowerpart is shown in the drawings, a compartment 614 containing medicament,an air passage 616 and an opening 617. The compartment is in a known wayconnected to the air passage 616 for dispensing of a metered dose ofmedicament to the patient during inhalation.

The device according to the invention comprises a mouthpiece 18 with aback and a front end 620, 622 in fluid communication with the airpassage. In the embodiment shown in FIGS. 30 and 32-35, the back end 620is pivotably arranged to an axis 624 inside the body so that themouthpiece may be pivoted between a rest/protected position, FIG. 35, toan activated, ready to use position, FIGS. 30 and 32. A torsion spring626 is arranged between the mouthpiece and the body for urging themouthpiece towards the activated position and for holding it in thatposition.

A protective cover or lid 628 is pivotably arranged to an axis 630. Theinside of the cover is arranged with a protruding surface 632. When theinhaler/mouthpiece is activated and ready to use, the mouthpiece hasswung to its protruding, inhalation, position by the torsion spring,whereby the upper side surface of the mouthpiece abuts the upper edge ofthe opening 617 pushed by the spring.

When the patient has inhaled the dose of medicament, he closes the coverby pivoting it. The inner surface of the cover then comes in contactwith the front end of the mouthpiece, which surface pivots themouthpiece into the body, FIGS. 33 and 34. When the cover is completelyshut, it is held in place by a fixating means (not shown) therebyholding the mouthpiece in the rest/protected position.

FIGS. 31 and 36-38 show another embodiment of the invention, where thesame components have the same reference numerals.

In this embodiment the mouthpiece is arranged slidable in the body. Themouthpiece is arranged with protrusions 634 attached to opposite side ofthe mouthpiece. The protrusions are slidably arranged in grooves 636 inthe body. The inner end of the mouthpiece is arranged with a downwardextending arm 638. A pusher spring 640 is arranged between themouthpiece and the body. An enclosing wall 642 is arranged around themouthpiece. With this design the whole interior of the body may act asan air passage for the inhaling air, and thus no specific air passage isto be arranged and connected to the mouthpiece. The wall also serves asa guide and support for the mouthpiece.

When the inhaler is activated, the mouthpiece protrudes through theopening by the spring and held in this position, while the protrusionsabut the outer ends of the grooves. When the patient has inhaled thedose of medicament, he closes the cover by pivoting it. The innersurface of the cover then pushes the mouthpiece whereby it slides in itslongitudinal direction 642 by the protrusions and the groove.

FIG. 39 shows an example of an inhaler for aerosol driven medicamentswith a pivoting mouthpiece. The pivoting point 650 is placed such thatthe nozzle 652 in fluid communication with the canister 654 is in linewith the mouthpiece 618 when it is in the inhaling position. A generaldesire in this respect is that the pivoting point is placed as close tothe canister/nozzle as possible to minimise the height of the inhaler,and as far to the protruding side of the inhaler/mouthpiece as possibleso that the mouthpiece protrudes such an extent that it is easily placedin the mouth. The pivoting mouthpiece is also provided with a coveringwall 656, which, when the mouthpiece is in the inhaling position, coversthe interior of the inhaler, which may comprise other mechanisms forhandling the inhaler. The protective cover/lid may also be arranged withholding means, not shown, for preventing the mouthpiece to pivot backwhen in the inhaling position.

FIG. 40 shows a mouthpiece according to the invention wherein themovable mouthpiece and the spray head with nozzle is made as onereplaceable unit. This arrangement is convenient when the inhaler assuch is intended for long time use. The mouthpiece and the spray headoften become clogged or smeared with medicament after some use.Therefore, it is practical that they may be removed as a unit forreplacement or cleaning.

For the different embodiments, the protective cover/lid may be opened bypressing or sliding a button, lever or the like, and placed on theinhaler in such a way as to coincide with the ergonomical conditions ofthe user. In order to ensure that the cover is not opened accidentally,it may comprise two buttons or activating points that have to pressed oractivated at the same time. It is also conceivable that the protectivecover is a sleeve, for example slidable in the longitudinal direction ofthe inhaler. The sleeve may also be so long that it constitutes themajor outer surface of the inhaler, and that the user holds the sleevewhen holding the inhaler. The upper part of the sleeve is open, throughwhich the inhaler body protrudes. By pressingthe upper end of the bodydownwards, it slides inside the sleeve, whereby the lower part of thebody, comprising the movable mouthpiece, is arranged below the sleeve,thus exposing the mouthpiece, and the inhaler is ready to use.

The device can further be provided with means for reactivating,returning and recharging means of the inhaler after delivery of a dose.These means may include placing the inhaler in a ready-to-use state,wherein the metered dose compartment is refilled/recharged, that themeans for delivering a dose, like pressure springs acting on an aerosolcanister, are re-tensioned, and the like. In this context, reference ismade to the Swedish patent application No. 99023494-1, which hereby isincorporated in its entirety. Preferably these means are activated bythe protective cover/lid when it is closed. Tensioning of springs andthe like is facilitated in that the protective cover/lid may be used asa lever, thereby reducing the force needed.

It is to be understood that the invention is not limited to theembodiments described above and shown on the drawings, but may bealtered within the scope of the patent claims.

In this respect it is conceivable that the mouthpiece may be pivotablearound a vertically arranged axis instead of a horizontal axis, whichaxis may coincide with the outlet of the metered dose compartment. Thisdesign has the advantage of requiring less space in that the mouthpieceis swung sideways in and out from the inhaler body, thus reducing theheight of the inhaler. It is also conceivable that the mouthpiece may beformed by several telescopically acting parts in order to obtain theprotruding effect.

The moving action of the mouthpiece from an activated position to aprotected rest position may also be obtained by other means, such ascam-shaped ribs or protrusions or some form of linkage between the coverand the mouthpiece.

1. An inhaling device for dispensing a metered dose of medicament from ametered dose chamber of a canister, comprising: a housing; a mouthpieceoperably connected to the housing and a flow path inside the housing,such that an airflow is created through the flow path when a userinhales through the mouthpiece; the canister being arranged inside thehousing, such that the canister is movable between a non-depressedposition and a depressed position for dispensing the metered dose ofmedicament from the metered dose chamber; an actuator assembly arrangedin the flow path and operably connected to the canister such that thecanister is activated to the depressed position for dispensing themedicament in response to the airflow through the mouthpiece and theflow path, wherein the actuator assembly includes at least a pressuremeans, a first holding means for holding the pressure means and therebypreventing the pressure means from depressing the canister, and areleasing means for disengaging the first holding means; and a returncontroller assembly operably connected to the actuator assembly andarranged to hold the canister in the depressed position and dispense themedicament for a period of time determined by the airflow and arrangedto release the canister from the depressed position when the airflowdrops below a certain threshold value, wherein the return controllerincludes at least a second holding means for holding the canister in thedepressed position and a releasing means for disengaging the secondholding means, and a medicament dispensing time period is measured basedon the period of time during which the airflow remains above thethreshold value to provide an indication of inhalation quality.
 2. Theinhaling device of claim 1, wherein the actuator assembly comprises aflap or vane.
 3. The inhaling device of claim 1, wherein the inhalingdevice includes a nozzle in fluid communication with the chamber, and anopening for dispensing the metered dose of medicament in fluidcommunication with the nozzle.
 4. The inhaling device of claim 1,wherein the actuator assembly includes a pressure spring means formoving the canister relative the inhaling device to vent the chamber,and the return controller includes a return spring means for moving thecanister relative the inhaling device to an unvented position againstthe force of the pressure spring means.
 5. The inhaling device of claim1, wherein the actuator assembly and the return controller assembly areoperated when the canister is positioned with its outlet facingdownwardly in the inhaling device.
 6. The inhaling device of claim 5,wherein the canister is refilled/recharged during deactivation of thecanister.
 7. The inhaling device of claim 1, wherein the inhaling devicefurther comprises detection/monitoring means for detecting/monitoringthe time between activation and deactivation of the canister.
 8. Theinhaling device of claim 1, wherein the return controller deactivatesthe canister when the user's airflow drops below the threshold value. 9.The inhaling device of claim 8, wherein the canister is reset duringdeactivation of the canister by the return controller.
 10. The inhalingdevice of claim 8, wherein the canister is reset during the user'sinhalation.